A night vision device (NVD) is an optical installment that allows images to be produced in levels of light approaching total darkness. They are most often used by the military and law enforcement agencies, but are available to civilian users. The term usually refers to a complete unit, including an image intensifier tube, a protective and generally water-resistant housing, and some type of mounting system. Many NVDs also include sacrificial lenses, IR illuminators, and telescopic lenses. NVDs are mounted appropriately for their specific purpose, with more general- purpose devices having more mounting options. For instance, the AN/PVS-14 is a monocular night vision device in use with the US military as well as by civilians. It may be mounted on the user's head for hands free use with a harness or helmet attachment, either as a monocular device, or in aligned pairs for binocular "night vision goggles" which provide a degree of depth perception as do optical binoculars. The AN/PVS-14 may also be attached to a rifle using a Pica tinny rail, in front of an existing telescopic or red dot sight, or attached to a single-lens reflex camera. Other systems, such as the AN/PVS-22 or Universal Night Sight, are designed for a specific purpose, integrating an image intensifier into, for example, a telescopic sight, resulting in a smaller and lighter but less versatile system.

Introduction
NVT allows us to see in the dark
Originally developed for military use
Now used for site security, surveillance as well as search and rescue
Evolved from bulky optical instruments in lightweight goggles through the advancement of image intensification technology.
Types of night vision
Categorized by generations
Each substantial change NVT establishes a new generation
Categorized into:
Generation-0
Generation-1
Generation-2
Generation-3
Generation-4

Generation-0
Created by US Army
Uses active infrared
A projection unit called IR illuminator is attached
Full moon operation
Use anode in conjunction with cathode to accelerate the electrons
Problems â€œacceleration causes distortion of image as well as reduction of life of the tube
Also, it was quickly duplicated by the hostile nations

Generation-1 (1960â„¢s)
Uses passive infrared
Uses ambient light provided by the moon and the stars
Donâ„¢t require a source of projected infrared light
Donâ„¢t work well on cloudy or moonless nights
One quarter moon operation
Uses same image-intensifier tube technology as Generation-0
Same problems as faced by the Generation-0

Generation-2 (1970â„¢s)
Offer improved resolution and performance over Generation-1 devices
Considerably more reliable
Able to see in extreme low light conditions due to the addition of microchannel plate(MCP) to the image-intensifier tube
The images are less distorted and brighter

Generation-3 (1990â„¢s)
Currently used by the US Army
Better resolution and sensitivity
Photocathode is made up of Gallium Arsenide
MCP is coated with an ion barrier
Tube life is increased
Generation-4 (2000â„¢s)
Known as filmless and gated technology
Shows significant improvement in both high- and low-level light environments
No ion barrier in MCP
Responds quickly to different lightning conditions
Reduced background noise
Enhances signal to noise ratio
Images are less distorted and brighter

Thermal imaging
This technology operates by capturing upper portion of the infrared light spectrum, which is emitted as heat
Hotter objects emit more of this light than the cooler objects
These elements then create a thermogram
Thermogram electric pulses display data

Image Enhancement
Image Enhancement
It is also known as Image intensification
Relies on image intensifier tube to collect an amplify infrared and visible light
Lens captures the light which is then sent to image intensifier tube
It has photocathode that converts photons into electrons
When electrons pass through MCP ,more electrons are presented
This causes chain reaction where atoms are released
Electrons reach phosphor screen and photons are released
Those phosphor create green image

Equipments
Scopes- monocular, handheld, better look at a specific object and then return to normal viewing conditions.
Goggles- binocular, handheld or worn, excellent for constant viewing
Cameras- send the image to a monitor for display or to a VCR for recording.

Conclusions
Although the term ``night vision'' currently encompasses three distinct technologies, it is the evolution of image intensification technology that first made devices practical and widely used.

Their success was the result of advancements in light amplification and resolution techniques.
References

IR emission occurs when some changes occurs in the atomic level of objects.

If energy is applied to an atom the electron in it jumps to higher energy level.

As the electron trends to return to its ground state, it release its energy as photons.

This photon has specific wavelength depends on its energy level.

Night vision can work in two ways.

Thermal Imaging
Image Enhancement

Thermal Imaging
The thermal imaging technology operates by capturing the upper portion of IR light spectrum. The infrared spectrum is emitted as heat by objects instead of simply reflected as light. The warm objects emit more IR light than cooler objects.
WORKING
A special lens focuses the IR light emitted by all of the objects in view.
The focused light is scanned by a phased array of IR detected elements.
This scanning create a very detailed temperature pattern called thermogram.
The thermogram created by the detector elements is translated into electric impulses.

The electric impulses are then send to a signal processing unit which translates them into data for the display.
The signal processing unit send the information to the display. Itâ„¢s colour depends on the intensity of IR emission.
The combination of all the impulses from all the elements create the image.

IMAGE ENHANCEMENT
Image enhancement systems are normally called NVDâ„¢s. NVDâ„¢s rely on a special tube called an image intensifier tube to collect and amplify IR and visible light.
Working

An objective lens captures near-IR light.
The gathered light is send to the image-intensifier tube. The power supply for this tube receives power from two N-cell or AA battery.
The image intensifier tube has a photo cathode, which is used to convert the photons into electrons.
When the electron pass through the tube, similar electrons are released from atoms and it multiplies in number through micro channel plate(MCP).

An MCP is a glass disc that has various microscopic holes and has metal electrodes on both sides.

When a electron from the photo cathode hit the first electrode of MCP they get accelerated.

As electron pass through the micro channels they release other electrons using a process called Cascaded secondary emission.

The new electron collide with atoms creating a chain reaction result in rapid increase of electron.

The micro channels are created at a slight angle to encourage electron collision.

At last the electron hit a screen coated with phosphorus. This cause phosphorus to reach exited state and release photons.

This photons create green image which characterize night vision.

The viewed image can be magnified and focused through occular lens.

CHARACTERISTICS
Textures, light and dark
The objects that are clearly visible on day appear dark and vice versa through night vision unit.

Fog and Rain
Fog and rain reflect more light towards the night vision unit and this may degrade its performance.

Honey comb

This is a faint hexagonal pattern witch is the result of the manufacturing process.
Black spots
A few is a inherent characteristics of night vision technology which remain constant and will not increase in size or number.
EQUIPMENTS
Night vision Equipments can be classified into three categories.
Scope

Goggle

Cameras
Scopes
Scopes are monocular can be handheld or mounted on a weapon.
Goggles
Goggles are binocular can be handheld or worn on the head.
Cameras
Cameras with night vision technology can send the images to a monitor or VCR for display or recording.
APPLICATIONS
Military
Law Enforcement
Hunting
Wild life observation
Surveillance
Security
Navigation
Hidden object detection
Entertainment
ADVANTAGES
Night vision devices are compact in size and is easily portable.

It is widely used in military purposes so it is reliable.

Itâ„¢s working is very simple so it is easy to use.

It is designed for a long life.
DISADVANTAGES
Night vision devices is very costly.

It cannot properly be used in rain and fog as it degrade its performance.

Poor quality images due to black spots.
CONCLUSION
The new generation began to discover the unique world that can be found after darkness falls. Thus in the modern times night vision technology become a part of our daily life. Night vision devices can be useful to you â€œ just be sure to get the right type of your needs.

"Night vision" as referenced here is that technology that provides us with the miracle of vision in total darkness and the improvement of vision in low light environment. Night vision has existed for more than fifty years. Its importance is remarkable mostly in warfare, though night vision has numerous uses. Modern hunters rely in night vision to hunt animals during the night without being exposed to them
Night vision has had many improvements throughout the course of history. Its beginning date back to Second World War when the Germans idealized a very effective way to easily use their sniper rifles during the night. This was later researched very deeply into because night vision proved to have a devastating advantage for those who used it.
There are currently two different technologies for night vision .The first one is thermal vision and second one is regular vision. Both of them are used for detect object, though they both have advantage and disadvantages for thermal vision is that it does not require any light whatsoever to function. On the other hands regular vision cannot function in complete darkness because they Use technology capable of multiplying exis

INTRODUCTION

"Night vision" as referenced here is that technology that provides us with the miracle of vision in total darkness and the improvement of vision in low light environment. Night vision has existed for more than fifty years. Its importance is remarkable mostly in warfare, though night vision has numerous uses. Modern hunters rely in night vision to hunt animals during the night without being exposed to them
Night vision has had many improvements throughout the course of history. Its beginning date back to Second World War when the Germans idealized a very effective way to easily use their sniper rifles during the night. This was later researched very deeply into because night vision proved to have a devastating advantage for those who used it.
Night vision uses a very complex mechanism some what similar to modern TV's As a matter of fact; more than 200 chemicals substances are needed in order to make night vision product work effectively
There are currently two different technologies for night vision .The first one is thermal vision and second one is regular vision. Both of them are used for detect object, though they both have advantage and disadvantages. On the other hands regular vision cannot function in complete darkness because they
Use technology capable of multiplying existent light by thousands of times -And not detect it from elsewhere.

HAI... I NEED THE ABSTRACT,REPORT,PPT OF NIGHT VISION TECHNOLOGY IN SIMPLE FORM.I HOPE YOU GUYS COULD HELP ME IN THIS AND IF U COULD, SEND ME TO sumishere[at]rediffmail.com AS SOON AS POSSIBLE. TANKING YOU.

Night vision technology, by definition, literally allows one to see in the dark. Originally developed for military use, it has provided the United States with a strategic military advantage, the value of which can be measured in lives. Federal and state agencies now routinely utilize the technology for site security, surveillance as well as search and rescue. Night vision equipment has evolved from bulky optical instruments in lightweight goggles through the advancement of image intensification technology.
The first thing you probably think of when you see the words night vision is a spy or action movie you've seen, in which someone straps on a pair of night-vision goggles to find someone else in a dark building on a moonless night. And you may have wondered

Night vision technology, by definition, literally allows one to see in the dark. Originally developed for military use, it has provided the United States with a strategic military advantage, the value of which can be measured in lives. Federal and state agencies now routinely utilize the technology for site security, surveillance as well as search and rescue. Night vision equipment has evolved from bulky optical instruments in lightweight goggles through the advancement of image intensification technology. The first thing you probably think of when you see the words night vision is a spy or action movie you've seen, in which someone straps on a pair of night-vision goggles to find someone else in a dark building on a moonless night. And you may have wondered "Do those things really work? Can you actually see in the dark?" The answer is most definitely yes. With the proper night-vision equipment, you can see a person standing over 200 yards (183 m) away on a moonless, cloudy night! Night vision can work in two very different ways, depending on the technology used. Night vision technology was developed by the US defense department mainly for defense purposes, but with the development of technology night vision devices are being used in day to day lives. In this seminar of mine I wish to bring out the various principles of working of these devices that have changed the outlook both on the warfront and in our common lives. Night Vision can work in two different ways depending on the technology used.
1.Image enhancement- This works by collecting the tiny amounts of light including the lower portion of the infrared light spectrum, those are present but may be imperceptible to our eyes, and amplifying it to the point that we can easily observe the image.
2:Thermal imaging- This technology operates by capturing the upper portion of the infrared light spectrum, which is emitted as heat by objects instead of simply reflected as light. Hotter objects, such as warm bodies, emit more of this light than cooler objects like trees or buildings. Image enhancement This works by collecting the tiny amounts of light, including the lower portion of the infrared light spectrum, that are present but may be imperceptible to our eyes, and amplifying it to the point that we can easily observe the image.
3 Thermal imaging
This technology operates by capturing the upper portion of the infrared light spectrum, which is emitted as heat by objects instead of simply reflected as light. Hotter objects, such as warm bodies, emit more of this light than cooler objects like trees or buildings. In this article, you will learn about the two major night-vision technologies. We'll also discuss the various types of night-vision equipment and applications. But first, let's talk about infrared light.

In this study we will attempt to disclose the major aspects of night vision technology and how it has evolved over the past forty years. Night vision is simply having the ability to see in the dark. In many night vision systems, the objective lens collects small particles of light called photons and focuses them on an image intensifier. Within the image intensifier lies a photocathode which absorbs light energy and converts it into electrons. When the highly intensified electron image strikes the phosphor screen, it causes the screen to emit light which can be seen with the human eye. This process allows one to see a reflected image that directly corresponds with the outside image they are viewing. Night vision technology is considered preeminent and is used throughout the world in various areas of life (“How Night Vision Works”).

INTRODUCTION

Have you ever got up in the middle of the night and stumbled over an object in the middle of the floor? Blinded by the darkness, you rush to the nearest light switch to get an illuminated view of the area. Well, stumble no more; through advancement in technology, special equipment has been produced to enable one to see through the darkness. We call these highly esteemed devices, night vision optics. Originally developed and used by the U.S. military to locate enemy targets at night; night vision optics or devices, better referred to as NVDs, have revolutionized the history of human vision.

A night vision device (NVD) is an optical instrument that allows images to be produced in levels of light approaching total darkness. They are most often used by the military and law enforcement agencies, but are available to civilian users. The term usually refers to a complete unit, including an image intensifier tube, a protective and generally water-resistant housing, and some type of mounting system. Many NVDs also include sacrificial lenses[1], IR illuminators, and telescopic lenses.
Night vision devices were first used in World War II, and came into wide use during the Vietnam War.[2][3] The technology has evolved greatly since their introduction, leading to several "generations" of night vision equipment with performance increasing and price decreasing.

With the proper night-vision equipment, you can see a person standing over 200 yards away on a moonless, cloudy night.

Originally developed for military use.

Federal and state agencies now routinely utilize the technology for site security, surveillance as well as search and rescue.
Various Night Vision Snaps
Night Vision Technology
Night Vision can work in two different ways depending on the technology used.

Collects the tiny amounts of light including the lower portion of the infrared light spectrum.

&

Amplify it to the point that we can easily observe the image.

How Image Enhancement works?
Objective lens captures ambient light and some near-infrared light.
The gathered light is sent to the image-intensifier tube.
The tube outputs a high voltage to the image-tube components.
The image-intensifier tube has a photocathode, which is used to convert the photons of light energy into electrons.
As the electrons pass through the tube, similar electrons are released from atoms in the tube, multiplying the original number of electrons using a microchannel plate (MCP) in the tube.

At the end of the image-intensifier tube, the electrons hit a screen coated with phosphors.
The energy of the electrons causes the phosphors to reach an excited state and release photons.
The green phosphor image is viewed through the ocular lens, which allows you to magnify and focus the image.
Thermal Imaging
Captures the upper portion of the infrared light spectrum, which is emitted as heat by objects.

Hotter objects, such as warm bodies, emit more of this light than cooler objects like trees or buildings. How Thermal Imaging Works?
A special lens focuses the IR emitted by all of the objects in view.
The focused light is scanned by a phased array of infrared-detector elements.
The detector elements create a very detailed temperature pattern called a thermogram.
The thermogram is translated into electric impulses
The impulses are sent to a signal-processing unit, that translates the information from the elements into data for the display.

The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the IR emission.
Thermal Imaging Devices
Two Types:

Conclusion
Night vision technology was developed by the US defense department mainly for defense purposes

Night Vision Technologies are now used in the daily lives.

While thermal imaging is great for detecting people or working in near-absolute darkness, most night-vision equipment uses image-enhancement technology.

Many people are beginning to discover the unique world that can be found after darkness falls

One estimate shows an entire battalion could be outfitted with the ability to "own the night" for less than two million dollars

In future many Other method will used for efficient way of working of Night Vision Technology Future Scope
The United States Air Force is experimenting with Panoramic Night Vision Goggles (PNVGs) which double the user's field of view to around 95 degrees by using four 16 mm image intensifiers tubes, rather than the more standard two 18 mm tubes.And lets hope that more and more advancements will be made in the field of night vision technologies so that we can also “own the night” one day…………
References
1. http://www.answer.com
2. http://www.nightvision.com
3. http://www.google.com
4. http://www.wikipedia.org

NIGHT VISION TECHNOLOGY
Abstract:
Apart from many technologies in the present world, NIGHT VISION TECHNOLOGY is one of the most used technologies, in many fields. This technology helps in discovering the world that is present in darkness. The implementation of this technology is done properly through night-vision equipment. This NIGHT VISION TECHNOLOGY uses the equipment NIGHT VISION DEVICES also called NVD`s for identifying a person who is approximately 183m away from the moonlight.
This uses the concept of infrared rays. In this technology it uses two methods for the detection. Both methods work in two different levels. The development in the technology has made its implementation to extend into many fields. The original purpose of night vision is was to locate enemy targets at night. But its requirement has been considered also in the fields of Surveillance, Hidden-object detection, Entertainment, Wild life detection and in Navigation.
My paper deals with the two methods by which this technology works.

presented by:
Y. Shiva kumarNIGHT VISION TECHNOLOGY.docx (Size: 191.99 KB / Downloads: 166)
NIGHT VISION TECHNOLOGY
Introduction:
 NVT allows us to see in the dark
 Originally developed for military use
 Now used for site security, surveillance as well as search and rescue
 Evolved from bulky optical instruments in lightweight goggles through the advancement of image intensification technology. Types of night vision:
 Categorized by generations
 Each substantial change NVT establishes a new generation
 Categorized into:
Generations- 0 , 1, 2 , 3 , 4 .Generation-0:
 Created by US Army
 Uses active infrared
 A projection unit called IR illuminator is attached
 Full moon operation
 Use anode in conjunction with cathode to accelerate the electrons
 Problems –acceleration causes distortion of image as well as reduction of life of the tube
 Also, it was quickly duplicated by the hostile nationsGeneration-1 (1960’s):
 Uses passive infrared
 Uses ambient light provided by the moon and the stars
 Don’t require a source of projected infrared light
 Don’t work well on cloudy or moonless nights
 One quarter moon operation
 Uses same image-intensifier tube technology as Generation-0
 Same problems as faced by the Generation-0Generation-2 (1970’s)
 Offer improved resolution and performance over Generation-1 devices
 Considerably more reliable
 Able to see in extreme low light conditions due to the addition of microchannel plate(MCP) to the image-intensifier tube
 The images are less distorted and brighterGeneration-3 (1990’s)
 Currently used by the US Army
 Better resolution and sensitivity
 Photocathode is made up of Gallium Arsenide
 MCP is coated with an ion barrier
 Tube life is increasedGeneration-4 (2000’s)
 Known as “filmless and gated” technology
 Shows significant improvement in both high- and low-level light environments
 No ion barrier in MCP
 Responds quickly to different lightning conditions
 Reduced background noise
 Enhances signal to noise ratio
 Images are less distorted and brighterThermal imaging
 This technology operates by capturing upper portion of the infrared light spectrum, which is emitted as heat
 Hotter objects emit more of this light than the cooler objects
 These elements then create a thermogram
 Thermogram àelectric pulsesà display data

PRESENTED BY
MANJEERA
ANITHANIGHT_ VISION_TECH_PPT.ppt (Size: 1.35 MB / Downloads: 211)
NIGHT VISION TECHNOLOGY
Introduction
 NVT allows us to see in the dark
 Originally developed for military use
 Now used for site security, surveillance as well as search and rescue
 Evolved from bulky optical instruments in lightweight goggles through the advancement of image intensification technology. Types of night vision
 Categorized by generations
 Each substantial change NVT establishes a new generation
 Categorized into:
Generation-0
Generation-1
Generation-2
Generation-3
Generation-4Generation-0
 Created by US Army
 Uses active infrared
 A projection unit called IR illuminator is attached
 Full moon operation
 Use anode in conjunction with cathode to accelerate the electrons
 Problems –acceleration causes distortion of image as well as reduction of life of the tube
 Also, it was quickly duplicated by the hostile nationsGeneration-1 (1960’s)
 Uses passive infrared
 Uses ambient light provided by the moon and the stars
 Don’t require a source of projected infrared light
 Don’t work well on cloudy or moonless nights
 One quarter moon operation
 Uses same image-intensifier tube technology as Generation-0
 Same problems as faced by the Generation-0Generation-2 (1970’s)
 Offer improved resolution and performance over Generation-1 devices
 Considerably more reliable
 Able to see in extreme low light conditions due to the addition of microchannel plate(MCP) to the image-intensifier tube
 The images are less distorted and brighterGeneration-3 (1990’s)
 Currently used by the US Army
 Better resolution and sensitivity
 Photocathode is made up of Gallium Arsenide
 MCP is coated with an ion barrier
 Tube life is increasedGeneration-4 (2000’s)
 Known as “filmless and gated” technology
 Shows significant improvement in both high- and low-level light environments
 No ion barrier in MCP
 Responds quickly to different lightning conditions
 Reduced background noise
 Enhances signal to noise ratio
 Images are less distorted and brighter
Thermal imaging
 This technology operates by capturing upper portion of the infrared light spectrum, which is emitted as heat
 Hotter objects emit more of this light than the cooler objects
 These elements then create a thermogram
 Thermogram àelectric pulsesà display data WORKING
 A special lens focuses the IR light emitted by all of the objects in view.
 The focused light is scanned by a phased array of IR detected elements.
 This scanning create a very detailed temperature pattern called thermogram.
 The thermogram created by the detector elements is translated into electric impulses. Thermal imaging
Thermal imaging devices
 Two types:
1. Uncooled.
2. Cryogenically cooled.
 Great for detecting people or working in near-absolute darkness Image Enhancement
 It is also known as Image intensification
 Relies on image intensifier tube to collect an amplify infrared and visible light
 Lens captures the light which is then sent to image intensifier tube
 It has photocathode that converts photons into electrons
 When electrons pass through MCP ,more electrons are presented
 This causes chain reaction where atoms are released
 Electrons reach phosphor screen and photons are released
 Those phosphor create green imagePerformance Attributes
 Sensitivity (photo response)- tube’s ability to detect the available light
 Signal- plays a key role in night vision’s performance
 Resolution- ability to dissolve detail in the imageTechnical Characteristics
 Textures, Light and Dark
 Depth Perception
 Fog and Rain
 Honeycomb
 Spots Equipments
Three categories
 Scopes
 Goggles
 Cameras Equipments
 Scopes- monocular, handheld, better look at a specific object and then return to normal viewing conditions.
 Goggles- binocular, handheld or worn, excellent for constant viewing
 Cameras- send the image to a monitor for display or to a VCR for recording. Applications
 Military
 Law enforcement
 Hunting
 Wild life observation
 Surveillance
 Security
 Navigation
 Hidden-object detection
 EntertainmentADVANTAGES
 Night vision devices are compact in size and is easily portable.
 It is widely used in military purposes so it is reliable.
 It’s working is very simple so it is easy to use.
 It is designed for a long life. DISADVANTAGES
 Night vision devices is very costly.
 It cannot properly be used in rain and fog as it degrade its performance.
 Poor quality images due to black spots.Conclusions
 Although the term ``night vision'' currently encompasses three distinct technologies, it is the evolution of image intensification technology that first made devices practical and widely used.
 Their success was the result of advancements in light amplification and resolution techniques.

Presented By:
Vrishali AtreyNight Vision.ppt (Size: 321.5 KB / Downloads: 120)
[/u]Introduction
 NVT allows us to see in the dark
 Originally developed for military use
 Now used for site security, surveillance as well as search and rescue
 Evolved from bulky optical instruments in lightweight goggles through the advancement of image intensification technology. Types of night vision
 Categorized by generations
Generation-1
Generation-2
Generation-3
Generation-4
 Mainly divided into 2 categories
Thermal imaging
Image EnhancementGeneration-1 (1960’s)
 Uses passive infrared
 Uses ambient light provided by the moon and the stars
 Don’t require a source of projected infrared light
 Don’t work well on cloudy or moonless nights
 One quarter moon operationGeneration-2 (1970’s)
 Offer improved resolution and performance over Generation-1 devices
 Considerably more reliable
 Able to see in extreme low light conditions due to the addition of micro channel plate(MCP) to the image-intensifier tube
 The images are less distorted and brighter. Generation-3 (1990’s)
 Currently used by the US Army
 Better resolution and sensitivity
 Photocathode is made up of Gallium Arsenide
 MCP is coated with an ion barrier
 Tube life is increased Generation-4 (2000’s)
 Known as “film less and gated” technology
 Shows significant improvement in both high- and low-level light environments
 No ion barrier in MCP
 Responds quickly to different lightning conditions
 Reduced background noise
 Enhances signal to noise ratio
 Images are less distorted and brighter
• Technologies used in night vision
• Night vision can work in two very different ways, depending on the technology used :
1. Image Enhancement.
2. Thermal Imaging.Thermal imaging
 This technology operates by capturing upper portion of the infrared light spectrum, which is emitted as heat
 Hotter objects emit more of this light than the cooler objects
 These elements then create a thermogram
 Thermogram àelectric pulsesà display data
• The basic components of a
“Thermal-imaging system”
• Thermal imaging Thermal imaging devices
 Two types:
1. Uncooled.
2. Cryogenically cooled.
 Great for detecting people or working in near-absolute darkness
Image Enhancement
 It is also known as Image intensification
 Relies on image intensifier tube to collect an amplify infrared and visible light
 Lens captures the light which is then sent to image intensifier tube
 It has photocathode that converts photons into electrons
 When electrons pass through MCP ,more electrons are presented
 This causes chain reaction where atoms are released
 Electrons reach phosphor screen and photons are released
 Those phosphor create green image
Image Enhancement
• Image Enhancement Technology used in NVDTechnical Characteristics
 Textures, Light and Dark
 Depth Perception
 Fog and Rain
 Honeycomb
 Spots Equipments
Three categories
 Scopes
 Goggles
 Cameras
 Scopes- monocular, handheld, better look at a specific object and then return to normal viewing conditions.
• Goggles- binocular, handheld or worn, excellent for constant viewing
• Cameras- send the image to a monitor for display or to a VCR for recording.
• Soldiers using
DARK INVADER night-vision GogglesApplications
 Military
 Law enforcement
 Hunting
 Wild life observation
 Surveillance
 Security
 Navigation
 Hidden-object detection
 Entertainment Conclusions
 Although the term “night vision” currently encompasses three distinct technologies, it is the evolution of image intensification technology that first made devices practical and widely used.
 Their success was the result of advancements in light amplification and resolution techniques.

SUBMITTED BY :
NEENA M. ROCHEdk.ppt (Size: 2.9 MB / Downloads: 129)
Introduction
 NVT allows us to see in the dark
 Originally developed for military use
 Evolved from bulky optical instruments in lightweight goggles through the advancement of image intensification technology. Types of night vision
 Categorized by generations
 Each substantial change NVT establishes a new generationCategorized into:
 Generation-0
 Generation-1
 Generation-2
 Generation-3
 Generation-4Generation-0
 Uses active infrared
 A projection unit called IR illuminator is
attached
 Full moon operation
 Use anode in conjunction with cathode to accelerate the electrons
 Problems –acceleration causes distortion of image as well as reduction of life of the tube
 Also, it was quickly duplicated by the hostile nationsGeneration-1 (1960’s)
 Uses passive infrared
 Uses ambient light provided by the moon and the stars
 Light amplification is around 1000x
 Don’t require a source of projected infrared light
 Don’t work well on cloudy or moonless nights
 One quarter moon operation
 Uses same image-intensifier tube technology as Generation-0
 Same problems as faced by the Generation-0Generation-2 (1970’s)
Offer improved resolution and performance over Generation-1 devices
Considerably more reliable
Able to see in extreme low light conditions due to the addition of micro channel plate(MCP) to the image-intensifier tube
The images are less distorted and brighter
Light amplification is around 20000xGeneration-3 (1990’s)
 Currently used by the US Army
 Better resolution and sensitivity
 Photocathode is made up of Gallium Arsenide
 MCP is coated with an ion barrier
 Tube life is increased
 Light amplification is around 30000 to 50000xGeneration-4 (2000’s)
 Known as “filmless and gated” technology
 Shows significant improvement in both high- and low-level light environments
 No ion barrier in MCP
 Responds quickly to different lightning conditions
 Reduced background noise
 Enhances signal to noise ratio
 Images are less distorted and brighterThermal imaging
 This technology operates by capturing upper portion of the infrared light spectrum, which is emitted as heat
 Hotter objects emit more of this light than the cooler objects
 These elements then create a thermogram
 Thermogram electric pulses display data Thermal imaging detectors
 Two types:
 Uncooled :The infrared detector elements are contained in a unit that operates at room temperature.
 Cryogenically cooled: These are the systems sealed inside a container that cools below 32F.
 Great for detecting people or working in near-absolute darkness
Image Enhancement
 It is also known as Image intensification
 Relies on image intensifier tube to collect an amplify infrared and visible light
 Lens captures the light which is then sent to image intensifier tube
 It has photocathode that converts photons into electrons
 When electrons pass through MCP ,more electrons are presented
 This causes chain reaction where atoms are released
 Electrons reach phosphor screen and photons are released
 Those phosphor create green imagePerformance Attributes
Sensitivity (photo response)- tube’s ability to detect the available light
Signal- plays a key role in night vision’s performance
Resolution- ability to dissolve detail in the imageTechnical Characteristics
Textures, Light and Dark
Depth Perception
Fog and Rain
Honeycomb
Spots Equipments
Three categories:
Scopes
Goggles
Cameras

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Night vision
Night vision is the ability to see in a dark environment. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range. Humans have poor night vision compared to many animals, in part because the human eye lacks a tapetum lucidum. Types of ranges
Spectral range
Night-useful spectral range techniques can sense radiation that is invisible to a human observer. Human vision is confined to a small portion of the electromagnetic spectrum called visible light. Enhanced spectral range allows the viewer to take advantage of non-visible sources of electromagnetic radiation (such as near-infrared or ultraviolet radiation). Some animals can see using much more of the infrared and/or ultraviolet spectrum than humans.Intensity range
Sufficient intensity range is simply the ability to see with very small quantities of light. Although the human visual system can, in theory, detect single photons under ideal conditions, the neurological noise filters limit sensitivity to a few tens of photons, even in ideal conditions.
Many animals have better night vision than humans do, the result of one or more differences in the morphology and anatomy of their eyes. These include having a larger eyeball, a larger lens, a larger optical aperture (the pupils may expand to the physical limit of the eyelids), more rods than cones (or rods exclusively) in the retina, a tapetum lucidum.
Enhanced intensity range is achieved via technological means through the use of an image intensifier, gain multiplication CCD, or other very low-noise and high-sensitivity array of photodetectors.Night vision technologies
Night vision technologies can be broadly divided into three main categories:Image intensification
Image intensification technologies work on the principle of magnifying the amount of received photons from various natural sources such as starlight or moonlight. Examples of such technologies include night glasses and low light cameras.Active illumination
Active illumination technologies work on the principle of coupling imaging intensification technology with an active source of illumination in the near infrared (NIR) or shortwave infrared (SWIR) band. Examples of such technologies include low light cameras.Thermal imaging
Thermal imaging technologies work by detecting the temperature difference between the background and the foreground objects.
Examples of some night vision technologiesNight glasses
Night glasses are telescopes or binoculars with a large diameter objective. Large lenses can gather and concentrate light, thus intensifying light with purely optical means and enabling the user to see better in the dark than with the naked eye alone. Often night glasses also have a fairly large exit pupil of 7 mm or more to let all gathered light into the user's eye. However, many people can't take advantage of this because of the limited dilation of the human pupil. To overcome this, soldiers were sometimes issued atropine eye drops to dilate pupils. Before the introduction of image intensifiers, night glasses were the only method of night vision, and thus were widely utilized, especially at sea. Second World War era night glasses usually had a lens diameter of 56 mm or more with magnification of seven or eight. Major drawbacks of night glasses are their large size and weight.Active infrared
Active infrared night vision combines infrared illumination of spectral range 700-1000nm (just below the visible spectrum of the human eye) with CCD cameras sensitive to this light. The resulting scene, which is apparently dark to a human observer, appears as a monochrome image on a normal display device.
Because active infrared night vision systems can incorporate illuminators that produce high levels of infrared light, the resulting images are typically higher resolution than other night vision technologies. Active infrared night vision is now commonly found in commercial, residential and government security applications, where it enables effective night time imaging under low light conditions. However, since active infrared light can be detected by night vision goggles, it is generally not used in tactical military operations.Laser range gated imaging
Laser range gated imaging is another form of active night vision which utilizes a high powered pulsed light source for illumination and imaging. Range gating is a technique which controls the laser pulses in conjunction with the shutter speed of the camera's detectors. Gated imaging technology can be divided into single shot, where the detector captures the image from a single light pulse to multi-shot, where the detector integrates the light pulses from multiple shots to form an image.
One of the key advantages of this technique is the ability to perform target recognition as opposed to detection with thermal imaging.Thermal vision(Thermal imaging cameras)
Thermal imaging cameras are excellent tools for night vision. They perceive thermal radiation and do not need a source of illumination. They produce an image in the darkest of nights and can see through light fog, rain and smoke. Thermal imaging cameras make small temperature differences visible. Thermal imaging cameras are widely used to complement new or existing security networks.Image intensifier
The image intensifier is a vacuum-tube based device that converts visible light from an image so that a dimly lit scene can be viewed by a camera or the naked eye. While many believe the light is "amplified," it is not. When light strikes a charged photocathode plate, electrons are emitted through a vacuum tube that strike the microchannel plate that cause the image screen to illuminate with a picture in the same pattern as the light that strikes the photocathode, and is on a frequency that the human eye can see. This is much like a CRT television, but instead of color guns the photocathode does the emitting.
The image is said to become "intensified" because the output visible light is brighter than the incoming IR light, and this effect directly relates to the difference in passive and active night vision goggles. Currently, the most popular image intensifier is the drop-in ANVIS module, though many other models and sizes are available at the market.

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